The purposes of the project are to determine the effects of abnormal glucose tolerance on outcome of the pregnancy, to determine long term prognosis for the women and their offspring, and to identify diabetes and impaired glucose tolerance during pregnancy in women in the Gila River Indian Community. Women with impaired glucose tolerance during pregnancy were at a higher risk of developing diabetes within 10 years than were women with normal glucose tolerance. However, they were at a lower risk than women who developed impaired glucose tolerance in the absence of pregnancy. Infants of diabetic mothers are more likely than infants of nondiabetic mothers to exhibit macrosomia, prematurity, perinatal mortality, and congenital malformations. Offspring of diabetic women are also at an increased risk of developing obesity and glucose intolerance during childhood and young adulthood. By means of a glucose tolerance test as well as chart review, the diabetes status of every woman is determined at two-yearly intervals and during the third trimester of each pregnancy. The characteristics of women who have diabetes or impaired glucose tolerance during the pregnancy are compared with those of women who are normal during the pregnancy and subsequently develop diabetes and with those of women who remain normal. These women and their offspring, after the age of 5 years, are followed at two yearly intervals and glucose tolerance tests are performed which include measurements of glucose and insulin. The offspring of diabetic women had higher rates of obesity at every age than did offspring of nondiabetic and prediabetic women. This finding was more marked in the younger age groups, suggesting that the effects of the diabetic pregnancy are seen mainly in childhood and adolescence and that other causes of obesity become more important in early adulthood. There was little difference in rates of obesity between offspring of nondiabetic and prediabetic women at any age. Few cases of diabetes developed before the age of 10 years, however, in older age groups, the offspring of diabetic women had a much higher prevalence of diabetes than either of the other two groups. Before the age of 25 years, the offspring of nondiabetic and prediabetic women had similar rates of diabetes. Thus, the metabolic abnormalities associated with the diabetic pregnancy result in long-term effects on the offspring including obesity and diabetes which in turn may contribute to transmission of risk for developing the same problems to the next generation.